You are currently viewing Oculomotor Nerve Disorder – Mnemonic

Here is a quick mnemonic “OCULOMOTOR NERVE PALSY to remember about Oculomotor Nerve Disorder

This can be valuable for patients as well as medical doctors, nurses & students doing their clinical rounds. You can also find it very useful for med exams like USMLE, MBBS, NEET PG, FMGE, NExT, MCAT & NCLEX exams

Oculomotor Nerve Disorder : How To Remember Easily ?

  • O – Oculomotor nerve: The third cranial nerve innervates the medial, inferior, and superior recti.
  • C – Complete palsy: Total palsy of the oculomotor nerve causes ptosis, a dilated pupil, and leaves the eye “down and out.”
  • U – Unopposed action: The lateral rectus and superior oblique muscles act unopposed in oculomotor nerve palsy, resulting in the eye being “down and out.”
  • L – Lid drooping: Ptosis, or drooping of the eyelid, is a common symptom in oculomotor nerve palsy.
  • O – Obvious findings: The combination of ptosis, a dilated pupil, and eye deviation in oculomotor nerve palsy is easily recognizable.
  • M – Multiple muscle weakness: Weakness of the eye muscles supplied by the oculomotor nerve can be encountered in partial palsy.
  • O – Oculomotor nerve involvement: Ptosis, pupil dilation, and weakness of eye muscles are signs that may indicate oculomotor nerve palsy.
  • T – Tumor or aneurysm: A compressive lesion, such as a tumor or aneurysm, may cause oculomotor nerve palsy with pupil involvement and pain.
  • O – Obtaining neuroimaging: Urgent neuroimaging, such as a CT or MR angiogram, should be done to exclude an aneurysm in oculomotor nerve palsy with pupil involvement and pain.
  • R – Rare isolated nuclear palsy: Isolated nuclear oculomotor palsy is rare and often accompanied by additional signs of brainstem damage.
  • N – Neurologic examination: A neurologic examination reveals additional signs suggesting brainstem damage in cases of oculomotor nerve palsy.
  • E – Eponymic designations: In Nothnagel’s, Benedikt’s, Claude’s, and Weber’s syndromes, various structures surrounding the oculomotor nerve are injured, leading to distinct symptoms.
  • R – Risk factors: Diabetes, hypertension, and vascular disease are major risk factors for microvascular infarction causing oculomotor nerve palsy.
  • V – Vascular etiology: Microvascular infarction along the oculomotor nerve’s course is a common cause of isolated, pupil-sparing oculomotor palsy.
  • E – Enigma of etiology: The cause of an isolated, pupil-sparing oculomotor palsy often remains unknown even after extensive testing.
  • P – Pain complaint: Patients with microvascular oculomotor nerve palsy usually complain of pain.
  • A – Aberrant regeneration: Trauma or compression of the oculomotor nerve can result in miswiring and aberrant regeneration of nerve fibers.
  • L – Levator muscle miswiring: Aberrant regeneration may cause elevation of the eyelid upon downgaze or adduction due to miswiring of sprouting fibers to the levator muscle.
  • S – Sprouting and pupil constriction: Aberrant regeneration can also lead to pupil constriction upon attempted adduction, elevation, or depression of the globe.
  • Y – Younger patients: Oculomotor nerve palsy in younger patients may be associated with trauma or compression rather than microvascular infarction.


Dr. Arin Nandi

Passionate About Medical Science & Helping Future Doctors Achieve Top Ranks In Medical Exams. He is professionally a dentist as well as a public health expert from JIPMER (1), (2)working in health department